aboutsummaryrefslogtreecommitdiff
path: root/lstring.c
diff options
context:
space:
mode:
authorRoberto Ierusalimschy <roberto@inf.puc-rio.br>1999-10-04 15:51:04 -0200
committerRoberto Ierusalimschy <roberto@inf.puc-rio.br>1999-10-04 15:51:04 -0200
commit4343420d4d559a7d4cdacdbc1fd61552dcf59f04 (patch)
tree57e0bdd41e2f3a4ab70d3150022569751e3d02ad /lstring.c
parent1f7103e05d01a6a4c300a73bcfc8d9b17b2c20a4 (diff)
downloadlua-4343420d4d559a7d4cdacdbc1fd61552dcf59f04.tar.gz
lua-4343420d4d559a7d4cdacdbc1fd61552dcf59f04.tar.bz2
lua-4343420d4d559a7d4cdacdbc1fd61552dcf59f04.zip
simplified version of `gc' tag method (only for userdata now).
Diffstat (limited to 'lstring.c')
-rw-r--r--lstring.c142
1 files changed, 31 insertions, 111 deletions
diff --git a/lstring.c b/lstring.c
index 13a123e3..633fbcd4 100644
--- a/lstring.c
+++ b/lstring.c
@@ -1,5 +1,5 @@
1/* 1/*
2** $Id: lstring.c,v 1.20 1999/08/16 20:52:00 roberto Exp roberto $ 2** $Id: lstring.c,v 1.21 1999/09/28 12:27:06 roberto Exp roberto $
3** String table (keeps all strings handled by Lua) 3** String table (keeps all strings handled by Lua)
4** See Copyright Notice in lua.h 4** See Copyright Notice in lua.h
5*/ 5*/
@@ -14,17 +14,13 @@
14#include "lua.h" 14#include "lua.h"
15 15
16 16
17#define NUM_HASHSTR 31
18#define NUM_HASHUDATA 31
19#define NUM_HASHS (NUM_HASHSTR+NUM_HASHUDATA)
20
21 17
22#define gcsizestring(l) (1+(l/64)) /* "weight" for a string with length 'l' */ 18#define gcsizestring(l) (1+(l/64)) /* "weight" for a string with length 'l' */
23 19
24 20
25 21
26static TaggedString EMPTY = {{NULL, 2}, 0L, 0, 22TaggedString luaS_EMPTY = {NULL, MAX_INT, 0L, 0,
27 {{{LUA_T_NIL, {NULL}}, 0L}}, {0}}; 23 {{{LUA_T_NIL, {NULL}}, 0L}}, {0}};
28 24
29 25
30 26
@@ -49,6 +45,16 @@ void luaS_init (void) {
49} 45}
50 46
51 47
48void luaS_freeall (void) {
49 int i;
50 for (i=0; i<NUM_HASHS; i++) {
51 if (L->string_root[i].hash != init_hash)
52 luaM_free(L->string_root[i].hash);
53 }
54 luaM_free(L->string_root);
55}
56
57
52static unsigned long hash_s (const char *s, long l) { 58static unsigned long hash_s (const char *s, long l) {
53 unsigned long h = 0; /* seed */ 59 unsigned long h = 0; /* seed */
54 while (l--) 60 while (l--)
@@ -57,12 +63,12 @@ static unsigned long hash_s (const char *s, long l) {
57} 63}
58 64
59 65
60static int newsize (stringtable *tb) { 66static int newsize (const stringtable *tb) {
61 int realuse = 0; 67 int realuse = 0;
62 int i; 68 int i;
63 /* count how many entries are really in use */ 69 /* count how many entries are really in use */
64 for (i=0; i<tb->size; i++) { 70 for (i=0; i<tb->size; i++) {
65 if (tb->hash[i] != NULL && tb->hash[i] != &EMPTY) 71 if (tb->hash[i] != NULL && tb->hash[i] != &luaS_EMPTY)
66 realuse++; 72 realuse++;
67 } 73 }
68 return luaO_redimension(realuse*2); 74 return luaO_redimension(realuse*2);
@@ -78,7 +84,7 @@ static void grow (stringtable *tb) {
78 /* rehash */ 84 /* rehash */
79 tb->nuse = 0; 85 tb->nuse = 0;
80 for (i=0; i<tb->size; i++) { 86 for (i=0; i<tb->size; i++) {
81 if (tb->hash[i] != NULL && tb->hash[i] != &EMPTY) { 87 if (tb->hash[i] != NULL && tb->hash[i] != &luaS_EMPTY) {
82 unsigned long h = tb->hash[i]->hash; 88 unsigned long h = tb->hash[i]->hash;
83 int h1 = h%ns; 89 int h1 = h%ns;
84 while (newhash[h1]) { 90 while (newhash[h1]) {
@@ -103,8 +109,8 @@ static TaggedString *newone_s (const char *str, long l, unsigned long h) {
103 ts->u.s.len = l; 109 ts->u.s.len = l;
104 ts->constindex = 0; 110 ts->constindex = 0;
105 L->nblocks += gcsizestring(l); 111 L->nblocks += gcsizestring(l);
106 ts->head.marked = 0; 112 ts->marked = 0;
107 ts->head.next = (GCnode *)ts; /* signal it is in no list */ 113 ts->next = ts; /* signal it is in no list */
108 ts->hash = h; 114 ts->hash = h;
109 return ts; 115 return ts;
110} 116}
@@ -115,8 +121,8 @@ static TaggedString *newone_u (void *buff, int tag, unsigned long h) {
115 ts->u.d.tag = (tag == LUA_ANYTAG) ? 0 : tag; 121 ts->u.d.tag = (tag == LUA_ANYTAG) ? 0 : tag;
116 ts->constindex = -1; /* tag -> this is a userdata */ 122 ts->constindex = -1; /* tag -> this is a userdata */
117 L->nblocks++; 123 L->nblocks++;
118 ts->head.marked = 0; 124 ts->marked = 0;
119 ts->head.next = (GCnode *)ts; /* signal it is in no list */ 125 ts->next = ts; /* signal it is in no list */
120 ts->hash = h; 126 ts->hash = h;
121 return ts; 127 return ts;
122} 128}
@@ -144,7 +150,7 @@ static TaggedString *insert_s (const char *str, long l, stringtable *tb) {
144 int j = -1; /* last empty place found (or -1) */ 150 int j = -1; /* last empty place found (or -1) */
145 int h1 = h%size; 151 int h1 = h%size;
146 while ((ts = tb->hash[h1]) != NULL) { 152 while ((ts = tb->hash[h1]) != NULL) {
147 if (ts == &EMPTY) 153 if (ts == &luaS_EMPTY)
148 j = h1; 154 j = h1;
149 else if (ts->u.s.len == l && (memcmp(str, ts->str, l) == 0)) 155 else if (ts->u.s.len == l && (memcmp(str, ts->str, l) == 0))
150 return ts; 156 return ts;
@@ -168,7 +174,7 @@ static TaggedString *insert_u (void *buff, int tag, stringtable *tb) {
168 int j = -1; 174 int j = -1;
169 int h1 = h%size; 175 int h1 = h%size;
170 while ((ts = tb->hash[h1]) != NULL) { 176 while ((ts = tb->hash[h1]) != NULL) {
171 if (ts == &EMPTY) 177 if (ts == &luaS_EMPTY)
172 j = h1; 178 j = h1;
173 else if ((tag == ts->u.d.tag || tag == LUA_ANYTAG) && buff == ts->u.d.v) 179 else if ((tag == ts->u.d.tag || tag == LUA_ANYTAG) && buff == ts->u.d.v)
174 return ts; 180 return ts;
@@ -200,115 +206,29 @@ TaggedString *luaS_new (const char *str) {
200 206
201TaggedString *luaS_newfixedstring (const char *str) { 207TaggedString *luaS_newfixedstring (const char *str) {
202 TaggedString *ts = luaS_new(str); 208 TaggedString *ts = luaS_new(str);
203 if (ts->head.marked == 0) 209 if (ts->marked == 0) ts->marked = 2; /* avoid GC */
204 ts->head.marked = 2; /* avoid GC */
205 return ts; 210 return ts;
206} 211}
207 212
208 213
209void luaS_free (TaggedString *l) { 214void luaS_free (TaggedString *t) {
210 while (l) { 215 L->nblocks -= (t->constindex == -1) ? 1 : gcsizestring(t->u.s.len);
211 TaggedString *next = (TaggedString *)l->head.next; 216 luaM_free(t);
212 L->nblocks -= (l->constindex == -1) ? 1 : gcsizestring(l->u.s.len);
213 luaM_free(l);
214 l = next;
215 }
216}
217
218
219/*
220** Garbage collection functions.
221*/
222
223static void remove_from_list (GCnode *l) {
224 while (l) {
225 GCnode *next = l->next;
226 while (next && !next->marked)
227 next = l->next = next->next;
228 l = next;
229 }
230}
231
232
233TaggedString *luaS_collector (void) {
234 TaggedString *frees = NULL;
235 int i;
236 remove_from_list(&(L->rootglobal));
237 for (i=0; i<NUM_HASHS; i++) {
238 stringtable *tb = &L->string_root[i];
239 int j;
240 for (j=0; j<tb->size; j++) {
241 TaggedString *t = tb->hash[j];
242 if (t == NULL) continue;
243 if (t->head.marked == 1)
244 t->head.marked = 0;
245 else if (!t->head.marked) {
246 t->head.next = (GCnode *)frees;
247 frees = t;
248 tb->hash[j] = &EMPTY;
249 }
250 }
251 }
252 return frees;
253}
254
255
256TaggedString *luaS_collectudata (void) {
257 TaggedString *frees = NULL;
258 int i;
259 L->rootglobal.next = NULL; /* empty list of globals */
260 for (i=NUM_HASHSTR; i<NUM_HASHS; i++) {
261 stringtable *tb = &L->string_root[i];
262 int j;
263 for (j=0; j<tb->size; j++) {
264 TaggedString *t = tb->hash[j];
265 if (t == NULL || t == &EMPTY)
266 continue;
267 LUA_ASSERT(t->constindex == -1, "must be userdata");
268 t->head.next = (GCnode *)frees;
269 frees = t;
270 tb->hash[j] = &EMPTY;
271 }
272 }
273 return frees;
274}
275
276
277void luaS_freeall (void) {
278 int i;
279 for (i=0; i<NUM_HASHS; i++) {
280 stringtable *tb = &L->string_root[i];
281 int j;
282 for (j=0; j<tb->size; j++) {
283 TaggedString *t = tb->hash[j];
284 if (t != &EMPTY) luaM_free(t);
285 }
286 if (tb->hash != init_hash) luaM_free(tb->hash);
287 }
288 luaM_free(L->string_root);
289} 217}
290 218
291 219
292void luaS_rawsetglobal (TaggedString *ts, TObject *newval) { 220void luaS_rawsetglobal (TaggedString *ts, const TObject *newval) {
293 ts->u.s.globalval = *newval; 221 ts->u.s.globalval = *newval;
294 if (ts->head.next == (GCnode *)ts) { /* is not in list? */ 222 if (ts->next == ts) { /* is not in list? */
295 ts->head.next = L->rootglobal.next; 223 ts->next = L->rootglobal;
296 L->rootglobal.next = (GCnode *)ts; 224 L->rootglobal = ts;
297 } 225 }
298} 226}
299 227
300 228
301const char *luaS_travsymbol (int (*fn)(TObject *)) {
302 TaggedString *g;
303 for (g=(TaggedString *)L->rootglobal.next; g; g=(TaggedString *)g->head.next)
304 if (fn(&g->u.s.globalval))
305 return g->str;
306 return NULL;
307}
308
309
310int luaS_globaldefined (const char *name) { 229int luaS_globaldefined (const char *name) {
311 TaggedString *ts = luaS_new(name); 230 TaggedString *ts = luaS_new(name);
312 return ts->u.s.globalval.ttype != LUA_T_NIL; 231 return ts->u.s.globalval.ttype != LUA_T_NIL;
313} 232}
314 233
234